New compact scrubber for odour removal in wastewater treatment plants

This work presents the performances of a new odour scrubber. The reactor is packed with a new structure which enables co-current operations at high gas velocities. Energy consumption and removal efficiency of sulphur compounds by oxidative alkaline scrubbing were studied. The influence of both superficial gas (U_SG) and liquid (U_SL) velocities, ranging from 5.6 to 28 m.s⁻¹ and 0.016 to 0.055 m.s⁻¹ respectively, were quantified. Thus, the range of 0.5 to 5 liquid-to-gas mass ratio (L/G) was studied. A comparison has been made with a previous study on static mixers (SM) and with classical random packed towers (PT). It has been shown that superficial liquid and gas velocities have a significant influence on these parameters. Hydrogen sulphide (H₂S) abatement reached values up to 99%. As concerns methylmercaptan (CH₃SH), the maximal removal efficiency was 87%. As a result, if well scaled-up, our reactor can be a small single stage efficient apparatus for the elimination of low concentrations of sulphur compounds as H₂S and CH₃SH in high flow rates of polluted gas effluents.